Source close to Eagle tells IBTimes UK she wants to give Corbyn more time to quit as Labour leader.

In a related video, crowds rally for Jeremy Corbyn in Parliament SquareIBTimes UK

Top Labour MP Angela Eagle has postponed the announcement of her leadership challenge in an effort to allow embattled Jeremy Corbyn to "do the right thing" and quit, a source close to the former shadow business secretary told IBTimes UK. Eagle, who recently resigned from the left-winger's shadow cabinet, was expected to launch her bid for the top job at 3pm BST today (30 June).

But the event has been delayed to give Corbyn more time to resign. A source close Eagle told IBTimes UK: "We think he wants to go, but we think people in his office are preventing him. He needs to do the right thing and go now."

A spokesman for the Labour leader hit back at the claims Corbyn's aides were blocking his resignation. "This is silly and deliberate briefing to destabilise his leadership," the spokesman told IBTimes UK. "He is personally determined to continue to carry out the role of leader that he was democratically elected to."

The comments come after Corbyn overwhelmingly lost a motion of "no confidence" from Labour's parliamentary party, following a string of resignations from his shadow cabinet over his EU referendum campaign performance. But the left-winger, who won Labour's 2015 leadership election with almost 60% of the vote, has vowed to stay on.

"Last month, Labour become the largest party in the local elections. In Thursday's referendum, a narrow majority voted to leave, but two thirds of Labour supporters backed our call for a Remain vote," Corbyn said in a 28 June statement.

"I was democratically elected leader of our party for a new kind of politics by 60% of Labour members and supporters, and I will not betray them by resigning. Today's vote by MPs has no constitutional legitimacy.

"We are a democratic party, with a clear constitution. Our people need Labour party members, trade unionists and MPs to unite behind my leadership at a critical time for our country."

McDonnell, a long-time ally of Corbyn, branded Labour's parliamentary party meeting on Monday night as "like a lynch-mob without the rope". He said: "On Monday night we had the parliamentary Labour party, which was not a meeting to enjoy. In fact, it was like a lynch-mob without the rope.

"MP after MP were getting up, urging Jeremy Corbyn to resign on the basis that we could not win elections with him. The irony of it was – the first item on that agenda of that meeting was welcoming the victor of the Tooting by-election [Rosena Allin-Khan]."